The present invention relates to the field of sensors for converting various physical quantities into electrical signals, and more particularly relates to a particular construction for such a sensor.
In the prior art, many known sensors have been constructed for sensing various physical quantities, such as temperature, pressure, vibration, and the like, for automatic control and measurement in various mechanical devices, such as, for example, automobiles, and these sensor elements are generally contained in enclosed spaces within protective casings made of metal or plastic, so as to prevent ingress of moisture, oil, dust, or other undesirable pollutants thereinto. In such sensors, since they produce electrical output signals which indicate the value of the physical quantity which they are measuring, electrically conducting lead wires must be connected to their respective sensor elements for transmitting the output electrical signals generated in these sensor elements. Thus, in this case, if such a lead wire extends across the enclosed space containing the sensor element, there may arise a problem that such an electrically conducting lead wire may touch or otherwise interfere with the operation of the sensor element while the sensor is being used, thereby interfering with the performance characteristics of the respective sensor element and producing an erroneous indicated value of the physical quantity which the sensor should measure.
Further, in the particular case of the construction of a sensor element which senses vibration in a solid body, and is attached thereto by an attaching portion, problems have arisen with respect to the provision of a cheap and simple, yet reliable, construction arrangement for such a sensor, which can provide a sensor of long life and durability, and yet which is not extremely expensive or troublesome to manufacture.
Further, especially in the case of a vibration sensor to be used on an automobile engine, the provision of electrical connections for electrical lead wires to be connected to the sensor element has sometimes been prone to poor contact and other malfunctions, or to entry, over a long period of time, of water, dust, oil, or other contaminants into the connecting portions between said lead wires and the sensor.